Disparities in exposure to chemicals with links to weight gain

  • Rates of obesity and overweight have skyrocketed, and some communities are harmed more than others.
  • Communities of color and people earning lower incomes are more exposed to “obesogens,” chemicals that can cause weight gain.
  • The federal government must do more to regulate and ban harmful chemicals and address environmental racism.


Rates of obesity and overweight in the U.S. have skyrocketed since 1980, from 14 percent to 42 percent. People of color and those living on low incomes bear a disproportionate burden.

There is no consensus about the reasons for this trend. A huge percent of the population hasn’t suddenly stopped exercising and started overeating, researchers say. They also note that changes to our genetic makeup can’t account for the steep rise.

Instead, in addition to changes that make our lives more sedentary and perhaps also shifts in genetic makeup, the sharp increase in obesity and overweight we are seeing may be caused by far more exposure to toxic chemicals in the environment, called obesogens. Communities who are already affected by environmental injustice carry the burden most of all.


In 1985, no state had an average obesity rate above 15 percent. Today more than 35 percent of adults in 16 states have obesity, according to the Centers for Disease Control and Prevention.

Communities of color have higher rates of obesity and overweight: About one in two Black people and 45 percent of Hispanic people had obesity between 2017 and 2018, compared to about 42 percent of white people, according to the CDC. Definitions of obesity and overweight are controversial and, some argue, culturally and racially inflected.

Income also plays a role. Kids in families earning lower incomes are more affected by obesity than are those in families with more resources. And the percentage of overweight adults in the U.S. goes down as income increases.

The health consequences of these disparities are far-reaching. People with obesity and overweight are more likely to suffer from chronic poor health and face a greater risk of Type 2 diabetes and other problems of metabolism, high blood pressure, high cholesterol, heart disease and stroke. Obesity is second only to smoking as a leading cause of death.

Understanding these disparities

These disparities aren’t universally understood: Four in five Americans believe obesity mostly comes down to individual responsibility, one study finds. The real problems are systemic, not individual, the authors say. The daily stresses of racism, the failures of an often cost-prohibitive health care system, the inaccessibility of affordable healthy food – these contribute to higher rates of obesity and overweight among people of color and those living with less income.

Another important factor contributing to who is most affected by obesity and overweight, many studies argue, is disparate exposure to obesogens.

What are obesogens?

Obesogens are toxic chemicals that can alter hormones and metabolism to make us gain weight. These substances can increase the production of fat cells, change their shape and size, and interact with processes that regulate our appetite and sense of fullness after a meal.

These chemicals may interact with genetics, nutrition and eating habits and other environmental conditions, like sleep, exercise and stress, and affect weight and metabolism. They can have other far-reaching effects, harming the developing brain and the reproductive and immune systems. Their damage can extend to the developing fetus and future generations.

Inequities in exposure

Obesogens are everywhere – in food, air, water and a wide array of consumer and industrial products and uses. Because of systemic racism and other inequities, including redlining and de facto segregation, industrial plants, freeways, stores full of highly processed food and other sources of toxic chemicals have long been situated in and near communities of color and low-income communities, who are harmed disproportionately.


Low-quality, highly processed food, like those containing high-fructose corn syrup, preservatives, and artificial sweeteners, flavorings and colorings, are likely to be more readily available at dollar stores and convenience stores, which are often located in communities of color and low-income communities.

And in these neighborhoods there may also be little or no access to more healthy food, leaving people with little option but to buy harmful, nutrition-poor food.

Air quality

People of color and those who experience economic difficulties are more likely to breathe polluted air. Thousands of drilling operations are located in formerly redlined communities. In  one study, the groups most exposed to six of the pollutants that cause poor air quality air were a racial or ethnic minority.

Proximity and density of traffic that produces airborne contaminants like particulate matter and nitrogen can affect childhood obesity. Half of U.S. kids with obesity will also have it as adults, if current trends continue.

People of color are more likely to breathe air contaminated by pesticides, some of which are obesogens. The farmworkers in California’s agricultural fields – overwhelmingly Hispanic – breathe contaminated air at work and, because of pesticide drift, at home.

The air is especially polluted near industrial animal farms, which tend to be located in proximity to communities of color. Particulate matter pollutes the air nearby. Drift from pesticides can get into the air after being sprayed in fields where cattle graze and in chicken houses.

Drinking water

Some research suggests that communities of color and people living on low income may be more likely to drink water contaminated by the “forever chemicals” known as PFAS. The Union of Concerned Scientists found people earning low income and people of color were more likely to live within 5 miles of a PFAS-contaminated site, which affects nearby drinking water.

A 2021 study by the Natural Resources Defense Council combined demographic census tract data with results of PFAS tests and found that 25 percent of California communities identified as the most vulnerable also have PFAS contamination. Of the 77 percent of these communities for which data is available, 69 percent had PFAS detections. One in five had the highest detections. More research is needed on the impact of PFAS on disadvantaged communities.

Children of color and kids living in families with low income are also more likely to drink water contaminated by the heavy metals arsenic and cadmium, both obesogens.

Consumer products

People are exposed to huge numbers of products at home and at work that may be contaminated with obesogens. This is especially the case for people of color, who tend to to be more exposed than white people to phthalates, for instance. These are a type of obesogen that makes plastic more pliable in a vast range of products, including cosmetics and personal care products, items used for cleaning and in health care settings, and other purposes, including any product with “fragrance” on the ingredients label.

Women of color use more personal care products than white women – 30 per day, on average, compared to 12 – and so are more exposed to the obesogens in them, including phthalates, fragrance, PFAS and formaldehyde, among many others.

We must regulate and clean up these toxic chemicals

Addressing the obesity epidemic needs to shift from finding a “cure” – thus far with little success – to prevention, and the key is to limit our exposure as much as possible.

The federal government is responsible for restricting or banning the harmful chemicals in our environment. But so far, it has largely failed to do so.

Progress is slowly being made on some fronts. The Food and Drug Administration recently agreed to reassess the health risks of BPA in food packaging, and the Environmental Protection Agency recently set lifetime health advisories for two of the most notorious PFAS chemicals.

But much more must to be done to address all the sources of our exposure. Consumers shouldn’t be required to shop their way out of the problem – an inadequate approach and one that’s out of reach for many.

It’s also up to the federal government to clean up the chemicals that have already done so much harm rather than leave it to the most affected communities – who can often least afford it – to pick up the tab.

What you can do

Until lawmakers and regulators step up to regulate the most widespread chemicals – the ones consumers can do little to avoid – the best approach is reducing the exposures you can control.

If you can’t afford to get the kind of water filtration that eliminates PFAS, for instance, you may at least be able to avoid consumer items that are nonstick because of the forever chemicals used to make them – like nonstick cookware and kitchen items and anything stain- and grease-resistant or waterproof.

Here are some other ways to reduce your exposure to obesogenic chemicals.

Eat “whole,” or unprocessed, foods. Foods lower on the food chain contain fewer or none of the chemicals considered obesogens, so eat fresh fruits and vegetables, whole grains and other similar foods. Avoid highly processed foods, which are more likely to contain obesogens, like high-fructose corn syrup, preservatives, and artificial sweeteners, flavorings and colorings.

For some foods, choose organic. To lower your exposure to pesticide residues, choose organic food whenever possible. To make this more affordable, consult our Shopper’s Guide to Pesticides in Produce™ and the Clean Fifteen™ list, which shows you the types of produce that contain less pesticide in non-organic versions. Our Dirty Dozen™ list shows which produce are best to buy organic, if possible.

Read labels for “fragrance” and choose “unscented” products. Fragrance” refers to a chemical or mix of chemicals in a huge variety of products. Consult EWG VERIFIED® to find personal care products and cleaners with safer ingredients. (You can also download our Healthy Living app for help finding safer ingredients on the go.)

Filter your drinking water. Find out whether your tap water is contaminated with obesogens by consulting EWG’s Tap Water Database, then take a look at our water filter buying guide to choose one that will work for you.

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